Both antisera and antitoxins are means of proactively combating infections. The introduction of compounds to which the immune system responds is an attempt to build up protection against microorganisms or their toxins before the microbes actually invade the body.

The use of antiserum and antitoxin preparations is now a standard avenue of infection control. The beginnings of the strategies dates to the time of Edward Jenner in the late eighteenth century. Then, Jenner used an inoculum of cowpox material to elicit protection against the smallpox virus.

Jenner's strategy of using a live organism to elicit an antibody response led to a "third-party" strategy, whereby serum is obtained from an animal that has been exposed to an antigen or to the microorganism that contains the antigen. This so-called antiserum is injected into the human to introduce the protective antibodies directly, rather than having them manufactured...